Softbank Maruyama CLS

AT&T announced last week the activation the first 400G optical connection between Dallas and Atlanta. This 400G  optical connection is not a trial, it is carrying live internet traffic across AT&T's network for their customers. AT&T believes the 400G optical connection is a first in the industry, which offers a significant upgrade to their production network, built on flexible, low-cost white box hardware. The 400G Dallas/Atlanta facility was deployed on an SDN-enabled Ultra Long Haul (ULH) system from Ciena, with 400G pluggable transceivers from InnoLight and white box was supplied by UfiSpace.

“The move from a 100G interface to 400G is a milestone for the communications industry, because it means we can continue to stay ahead of the tsunami of data demand we’ve seen over the last decade-plus,” said Andre Fuetsch, executive vice president and chief technology officer, AT&T. “This accomplishment also speaks to the tremendously collaborative ecosystem we’ve helped foster with key innovators in optical technology, white box hardware, and software-defined networking. Ciena, UfiSpace, Broadcom, and InnoLight have brought great ideas and technologies to bear to make 400G a reality.”

5G is coming fast. AT&T plans to have 5G nationwide in the first half of 2020. And AT&T will begin deploying 400G across their network in 2020. AT&T has been planning for this upgrade for a long time, and a large portion of the optical network equipment installed over the last year can be upgraded to 400G with a simple software update, making for a seamless transition.

The 400G Dallas/Atlanta facility was deployed on an SDN-enabled Ultra Long Haul (ULH) system from Ciena. The 400G circuit was routed and configured completely through software using Ciena’s Manage, Control and Plan (MCP) domain controller. The 400G transport was terminated in the Dallas and Atlanta offices by a white box router from UfiSpace that is compliant with the Broadcom Jericho2 Distributed Disaggregated Chassis (DDC) design that AT&T recently submitted to the Open Compute Project (OCP).

400G pluggable transceivers from InnoLight were installed in the white box router and Ciena transponder to create the cross-office connectivity between the packet and optical technologies. Ciena’s MCP controller is integrated into AT&T’s ONAP management and control framework using an Application Programming Interface (API) specified by the Open ROADM Multi-Source Agreement (MSA).

The optical transport system consists of a new 400G transponder based on Ciena’s WaveLogic Ai coherent optical technology. The Ciena Reconfigurable Optical Add/Drop Multiplexors (ROADMs) have been upgraded with new software to support a sophisticated feature known as flex grid. This allows AT&T, through software control, to optimize the allocation of spectrum on the long-haul fiber based on the required speed and reach of each wavelength.

The Broadcom Jericho2 white box was supplied by UfiSpace and provides 10 x 400G interfaces on a 2RU “pizza box”. The white box uses the Broadcom Jericho2 packet processing chip, a state-of-the-art chip designed to meet the demanding needs of a service provider.

While the smallest component in the solution, the 400G pluggable optical transceiver is also one of the most critical. The QSFP56DD-FR4 form factor is about the size of a pack of gum but it is packed with technology. The transceiver supplied by InnoLight conforms with the QSFP-DD MSA and is capable of transporting 400G signals on up to 2 kilometers of single-mode fiber.